1. Field of Invention
The invention relates to an ink jet recording apparatus and more particularly, to an ink suction mechanism.
2. Description of Related Art
An ink jet printer performs printing by ejecting ink from nozzles of a print head onto a recording medium. Viscous ink resulting from an evaporation of a solvent through nozzle openings, solidified ink, dust attached to the print head, or air bubble included in the ink affect the printing operation or printing quality. To prevent the adverse effects on the printing operation or the printing quality, the nozzle openings of the print head are covered by a cap member when the print head is idle. When necessary, a cleaning operation for the print head is performed by suctioning the ink from the nozzles to clear nozzle clogging caused by solidified ink, fine dust or foreign material, or air bubbles included in the ink. As the ink is suctioned from the nozzles during the cleaning operation, a nozzle surface is wet with ink. To prevent poor printing operation, the ink on the nozzle surface is wiped off by a wiping member.
In a drop-on-demand ink jet printer that ejects, based on print data, ink droplets only when they are needed to print on a recording media, as the nozzles are less frequently operated, ink viscosity or ink colorant density will be increased, leading to unstable ink ejection or no ink ejection. To remove the viscous ink from the nozzles, a flushing operation for recovering ink ejecting performance of the nozzles is periodically performed during the printing operation.
The ink suctioned during the cleaning operation is discharged into a waste ink tank, using, for example, a pump. Because an amount of the ink ejected during the flushing operation is relatively small as compared with the amount of the ink suctioned during the cleaning operation, the ink ejected from the print head by the flushing operation during the printing operation is absorbed material, such as a spongy foam. The ink wiped by the wiping member is not suctioned into a tank or absorbed in an absorbing material, because the wiping member only wipes off such a small amount of the ink that stays on the print head due to the surface tension.
When a large-volume printing job is performed, such as on a business scene, or when an hour-long printing separation is performed, the amount of the ink absorbed or wiped during the flushing or wiping operation increases. The ink jet printer may eventually become dirty with the ink if the ink attached to the wiping member is not removed. The absorbing material that absorbs the ink ejected during the flushing operation may have to be replaced frequently according to the absorbing capacity of the absorbing material. Providing an absorbing material large enough to accommodate an operating life of the ink jet printer does not satisfactorily meet the demands on the downsizing of the ink jet printer and further leads to increases in manufacturing costs.